A comet is heading for Mars, and there is a chance that it might hit the Red Planet in October 2014. An impact wouldn't necessarily mean the end of NASA's Mars program. But it would transform the program along with Mars itself.

Comet ISON is heading for a Thanksgiving Day brush with the sun, but first it's going to pay a visit to the Red Planet. Mars rovers and satellites will have a ringside seat for the comet's close approach on Oct. 1st.

On Nov. 28th. Comet ISON will have a perilous close encounter with the Sun. In today's story from Science@NASA, experts discuss what might happen if the comet gets hit by a solar storm at point-blank range.

Comet ISON is plunging toward the sun for a perilous pass through the solar atmosphere on Thanksgiving (Nov. 28th). In today's story from Science@NASA, a leading expert lays out some possible outcomes for the sundiving comet--from premature disintegration to spectacular survival.

In a milestone accomplishment, NASA's Curiosity rover has drilled into a rock on Mars and gathered material from its interior. This is the first time any robot has drilled into a rock to collect a sample on Mars.

Life as we know it doesn't thrive on planets without ozone layers, which is why the recovery of Earth's ozone layer is so important. A new instrument slated for launch to the ISS will monitor our planet's protective ozone cocoon with greater depth and precision than ever before.